MX2012005981A

MX2012005981A - Extruded fiber reinforced cementitious products having stone-like properties and methods of making the same.

Info

Publication number: MX2012005981A
Application number: MX2012005981A
Authority: MX
Inventors: Simon K Hodson; Per Just Andersen
Original assignee: Khashoggi E Ind
Priority date: 2009-11-24
Filing date: 2010-11-19
Publication date: 2012-11-23
Also published as: EP2504136A1; US20120270971A1; US20150239781A1; CN106082826A; US20110120349A1; WO2011066192A1; US9028606B2; EA201200774A1; EA028213B1; RU2012125994A; KR20120123285A; CN102712103A; EP3088149A1; EP2504136B1

Abstract

A cementitious composite product that can function as a substitute for stone and solid surface materials, such as granite, marble, and engineered stone is provided. Furthermore methods for manufacturing the cementitious composite product using an extrudable cementitious composition that can be extruded or otherwise shaped into stone-like building products that can be used as a substitute for many known stone products is disclosed. In one embodiment, the cementitious composite products can be manufactured more cheaply to be as tough or tougher and more durable than stone and solid surface materials.

Description

CEMENTED PRODUCTS REINFORCED WITH EXTRUDED FIBER THAT HAVE PROPERTIES SIMILAR TO THE STONE AND METHODS TO MAKE THEM ANTECEDENTS 'OF THE DESCRIPTION The present disclosure relates generally to cementitious building products containing high amounts of reinforcing fibers and more particularly, to extrudable compositions for use in the fabrication of ultra-high strength cementitious composite building products having stone-like properties.

The success of the building and construction industry is largely determined by the properties available for use in construction. Many materials have been used historically and currently, but each has one or more significant limitations, as further described in the following table.

As the availability of naturally occurring high quality materials such as stone and wood becomes scarcer, the need for manufactured products becomes increasingly important. Specifically, there is a need in the design and construction of buildings with concrete and steel for manufactured products that have high durability, low cost, high strength and hardness per unit mass, and that are aesthetically pleasing.

On the other hand, in conventional building products, 90% of the mass and volume of concrete is required only to support itself in the position and form; only 10% 'is actually used in the dynamic or mobile load capacity of the structure. Similarly, 75% of the mass and volume of steel used in a building is to stand on its own and maintain its position and shape; only 25% is actually used in the dynamic or mobile load capacity of the structure. In addition, although concrete has historically been recognized as having high compressive strength, the compressive strength of concrete is not usable. Rather, it is its resistance to bending or to the tension that is required, and the resistance to bending or tension is so low that in most cases it is assumed to be zero.

Based on the above, it would be a great advantage and advance in the construction industry to have a cementitious product that could be molded and shaped locally but that would have a much higher resistance to bending and tension so that little or no reinforcement of Steel would be required in the structure. It would also be an advantage if such a cementitious material were of a lower bulk density and had a greatly improved volume density ratio. This would increase the amount of concrete available for the dynamic loading capacity of the building.

Previous attempts to use fiber reinforced concrete have generally been limited by many factors. One factor is the difficulty of uniformly mixing and distributing the fibers more than 3% by volume throughout a high strength water cement ratio composition. The second factor is the rapid reduction in the rheology of the concrete that makes the shaping and placement of the concrete material much more difficult.

Accordingly, it would be advantageous to provide a cementitious composite product and method to be the cementitious composite product to be used in building products as an effective substitute in cost for stone and solid surface materials. The cementitious composite product could be manufactured to be harder and more durable (ie less brittle) than stone and solid surface materials without the use of reinforcing members such as rebar. On the other hand, it would be beneficial to provide cementitious composite products that could be used as a substitute for stone materials.

BRIEF DESCRIPTION OF THE DISCLOSURE The present disclosure relates to cementitious composite products (also required as building products or cementitious composite building products) that can function as a substitute for stone and solid surface materials. Specifically, the disclosed compositions and manufacturing processes have a flexural and tensile strength increased by more than 10 times as compared to conventional products. The products provide ease of molding and shaping for a wide variety of usable materials or construction products. In addition, compositions and processes make cementitious building materials that are hetically pleasing superior in a very low cost and weight. These cementitious materials are not brittle and do not chip or crack similar to the natural synthetic stone commonly used in construction. Additionally, they have all the advantages of the standard Portland Cement Concrete but are 10 times stronger and 100 times harder in 1/3 less weight. The products are non-flammable, highly durable and can be manufactured locally. A final advantage of these materials is that they get all the resistance required for use within 24 to 48 hours and do not need the typical 28-day period of other cementitious materials to achieve the performance requirement.

Accordingly, in one aspect, the present disclosure is directed to a cementitious composite product having stone-like properties. The product comprises an extrudable cementitious composition comprised of a hydraulic cement, aggregate, a rheology modification agent and fibers substantially homogeneously distributed through the extrudable cementitious composition and included in an amount greater than about 2% (by volume of the cementitious extrudable composition). The cementitious composite product has a hardness value of at least 4 MOH and a bulk density of about 1.3 g / cm 3 to about 2.3 g / cm 3.

In another aspect, the present disclosure is directed to a method for manufacturing a cementitious composite product having stone-like properties. The method comprises: mixing together water, fibers and a rheology modifying agent to form a fibrous mixture in which the fibers are substantially homogeneously dispersed; adding a mixture of hydraulic cement and aggregate to the fibrous mixture to produce an extrudable cementitious composition having a plastic consistency and including fiber in a concentration greater than about 2% by volume of the extrudable cementitious composition; extruding the extrudable cementitious composition into a fresh intermediate extruded material having a predefined cross-sectional area, the extruded material which is stable in shape in the extrusion and capable of substantially retaining the cross-sectional area to allow handling without breaking; and causing or allowing the hydraulic cement to be cured to form the cementitious composite product, wherein the cementitious composite has a hardness value of at least 4 MOH and a bulk density of about 1.3 g / cm3 to about 2.3 g / cm3.

Other objectives and characteristics will be partly evident and partly pointed out later in the present.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1A is a schematic diagram illustrating one embodiment of an extrusion process for manufacturing a cementitious composite building product; Figure IB is a schematic diagram illustrating an embodiment of an extrusion die head for manufacturing a cementitious composite building product having a continuous hole extending therethrough; Figure 1C is a perspective view illustrating modalities of the cross-sectional areas of extruded composite cement building products; Y Figure 2 is a schematic diagram illustrating one embodiment of a roller extrusion process for manufacturing a cementitious composite building product.

DETAILED DESCRIPTION OF THE DISCLOSURE It has been found that cementitious composite products can be made to have stone-like properties to be cheaper and more durable substitutes for stone and solid surface products, such as countertops, tile, siding, shingles and the like, as well as other non-architectural products such as pre-cast and pre-formed materials. The terminology used herein is used for the purpose of describing particular modalities only and is not intended to be limiting.

The terms "aggregate" and "aggregate fraction" refer to the fraction of concrete that is generally non-hydraulically reactive. The aggregate fraction is typically comprised of two or more differently sized particles, often classified as fine aggregates and coarse aggregates.

As used herein, the terms "fine aggregate" and "fine aggregates" refer to solid particulate materials that are smaller than 5 mm in size.

As used herein, the terms "coarse aggregate" and "coarse aggregates" refer to solid particulate materials that are retained in a No. 4 sieve (ASTM C125 and ASTM C33). Examples of commonly used coarse aggregates include 3/8 inch rock and 3/4 inch rock.

The term "multi-component" refers to fiber-reinforced extrudable cementitious compositions and extruded composite products prepared therefrom, which typically include three or more chemically or physically distinct materials or phases. For example, these resulting extrudable cementitious compositions and building products may include components such as rheology modifying agents, hydraulic cements, other hydraulically curable materials, hardening accelerators, hardening retardants, fibers, inorganic aggregate materials, organic aggregate materials, dispersants. , water and other liquids. Each of these broad categories of materials imparts one or more unique properties to the extruded compositions prepared therefrom as well as to the final product. Within these broad categories it is also possible to include different components (such as two or more inorganic aggregates or fibers) that can impart different, but complementary, properties to the extruded product.

The terms "hydraulically curable composition" and "cementitious composition" are proposed to refer to a broad category of compositions and materials that contain both a hydraulically hardenable binder and water as well as other components, such as aggregates and fibers, without considering the degree of hydration or cured that has taken bind. As such, the cementitious materials include hydraulic pastes or hydraulically curable compositions in a fresh (ie, non-hardened, soft or moldable) state and a hardened or cured cementitious composite product.

The term "homogeneous" is intended to refer to a composition that is uniformly mixed so that at least two random samples of the composition have approximately or substantially the same amount, concentration and distribution of a component.

The terms "hydraulic cement", "hydraulically hardenable binder", "hydraulic binder" or "cement" are intended to refer to the component or combination of components within a cementitious or hydraulically hardenable composition that is an inorganic binder such as, for example, Portland cements. , volatile ash and plasters that harden and heal after being exposed to water. These hydraulic cements develop increased mechanical properties such as hardness, compressive strength, tensile strength, flexural strength, and surface bonding of the component (eg, bonding the aggregate to cement) by reacting chemically with water.

The terms "hydraulic paste" or "cement paste" are proposed to refer to a mixture of hydraulic cement and water in the fresh state as well as the hardened paste resulting from the hydration of the hydraulic binder. As such, within a hydraulically hardenable composition, the cement paste binds together the individual solid materials, such as fibers, cement particles, aggregates and the like.

The terms "fiber" and "fibers" include both natural and synthetic fibers. Fibers typically having a dimensional ratio of at least about 10: 1 are added to an extrudable cementitious composition to increase elongation, deflection, hardness and fracture energy, as well as the flexural and tensile strength of the resulting extruded composite. or finished building product. The fibers reduce the likelihood that fresh extruded material, extruded products and hardened or cured products produced therefrom will break or break when forces are applied to them during handling, processing and curing. Also, the fibers can absorb water and reduce the effective water / cement ratio.

The term "fiber reinforced" is proposed to refer to cementitious compositions reinforced with fiber including fibers to provide some structural reinforcement to increase a mechanical property associated with a fresh extruded material, extruded products, and hardened or cured compounds as well as the building products produced therefrom. Additionally, the key term is "reinforced", which clearly distinguishes the extrudable cementitious compositions, the fresh extruded material and the cured building products of the present disclosure from the curable compositions and conventional cementitious products. The fibers primarily act as a reinforcing component to specifically add tensile strength, flexibility and hardness to the building products as well as to reinforce any of the cut or formed surfaces thereon. Because they are substantially homogeneously dispersed, building products do not separate or delaminate when exposed to moisture as products can do using conventional processes.

The term "mechanical property" is intended to include a property, variable or parameter that is used to identify or characterize the mechanical strength of a substance, composition or product of manufacture. Accordingly, a mechanical property may include the amount of elongation, deflection or compression before breaking or breaking, stress and / or deformation before rupture, tensile strength, compressive strength, Young's modulus, rigidity, hardness, deformation, resistance and the like.

The terms "extruded material", "extruded form" or "extruded product" are proposed to include any form of known or future designed products that are extruded using the extrudable cementitious compositions and methods of the present disclosure. For example, the extruded compound can be prepared in countertops, tiles, exterior cladding and tiles. Additionally, an initially extruded building product can be extruded as a "rough shape" and then shaped, polished, ground or otherwise refined into a manufacturing product, which is proposed to be included by use of the present terms.

The term "extrusion" can include a process where a material is processed or pressed through an opening or through an area that has a certain size for the shape of the material to conform to the opening or area. As such, an extruder that presses a material through a mold opening can be an extrusion shape. Alternatively, roller extrusion, which includes pressing a composition between a set of rollers, may be another form of extrusion. Roller extrusion is described in more detail below in Figure 2. In general, extrusion refers to a process that is used to form a mouldable composition without cutting, grinding, sawing or the like, and usually includes pressing or passing of the material through an opening having a predefined cross-sectional area.

The terms "hydrated" or "cured" are proposed. to refer to a level of a hydraulic reaction that is sufficient to produce a hardened cementitious building product that has obtained a substantial amount of its maximum potential or strength. However, cementitious compounds or extruded building products may continue to be hydrated or cured longer after they have reached significant hardness and a substantial amount of their maximum strength.

The terms "fresh" "fresh material" "fresh extruded material" or "fresh state" are proposed to refer to the state of a cementitious composition that has not yet achieved a substantial amount of its ultimate strength; however, the "fresh state" is proposed to identify that the cementitious composition has enough cohesiveness to retain an extruded form before being hydrated or cured. As such, a freshly extruded extruded material comprised of hydraulic cement and water should be considered to be "fresh" before a substantial amount of hardening or curing has taken place. The fresh state is not necessarily a clear cut line of demarcation as to the amount of curing or hardening that has taken place, but it should be considered as that is the state of the composition before it is substantially cured. Thus, a cementitious composition is in the fresh post-extrusion state and before it is substantially cured.

The term "stable in form" is proposed to refer to the condition of a fresh extruded material immediately in the extrusion which is characterized by the extruded material having a stable structure that does not deform under its own weight. As such, a fresh extruded material that is stable in shape can retain its conformation during handling and further processing.

The term "compound" is intended to refer to a stable composition in a form that is comprised of various components such as fibers, rheology modifiers, cement, aggregates, hardening accelerators and the like. As such, a composite is formed as the hardness or shape stability of the fresh extruded material increases, and can be prepared in a building or construction product.

The term "stone-like" or "stone-like properties" is proposed to refer to cementitious compositions and building properties of extruded cementitious compounds having a hardness value of at least 4 MOH, more adequately, at least about 5 MOH, still more suitably a hardness of at least about 6 MOH, and even more suitably a hardness of 7 to 8 MOH.

In one aspect, a cementitious composite product having stone-like properties is provided. The composite product includes an extrudable cementitious composition. The cementitious composite product has a hardness value of at least 4 MOH and a bulk density of at least 1.3 g / cm 3. More suitably, the cementitious composite product has a bulk density of about 1.3 g / cm3 to about 2.3 g / cm3.

EXTRUTABLE CEMENTOUS COMPOSITIONS USED TO MAKE THE CEMENTOUS COMPOSITE PRODUCT The extrudable cementitious compositions used to make extruded cementitious composite building products include water, hydraulic cement, fibers, aggregate, a rheology modifying agent, and optionally, a hardening accelerator or a hardening retardant. In addition to these components, the extrudable cementitious compositions can be mixed with other mixtures to give an extruded cementitious composite product having the desired properties as described more fully below. More particularly, cementitious composite products are formulated to have greater hardness and compressive strength as compared to ordinary concrete, and have greater hardness in order to better mimic the properties of stone and solid surface materials. In addition, the cementitious composite products of the present disclosure show flexibility, distinct from conventional stone products.

A. Hydraulic cement, water and aggregate Hydraulic cements are materials that can set and harden in the presence of water. The cement may be a Portland cement, modified Portland cement or masonry cement. For purposes of this description, Portland cement includes all cementitious compositions having high tricalcium silicate content, including Portland cement, cements that are chemically similar or analogous to Portland cement, and cements that fall within specification C -150-00 of ASTM. Portland cement, as used commercially, means a hydraulic cement produced by spraying vitreous brick (clinker), comprising hydraulic calcium silicates, calcium aluminates and calcium aluminoferrites, and usually containing one or more forms of sodium sulphate. calcium as an intermolida addition. Portland cements are classified in ASTM C 150 as Type I II, III, IV and V. Other hydraulically hardenable materials include ground granulated blast furnace slag, hydraulic hydrated lime, white cement, slag cement, calcium aluminate cement, cement silicate, phosphate cement, high alumina cement, magnesium oxychloride cement, oil well cements (eg, Type VI, VII and VIII) and combinations of these and other similar materials.

Pozzolanic materials such as slag, class F volatile ash, class C volatile ash and silica fume can also be considered to be hydraulically hardenable materials when used in combination with conventional hydraulic cements, such as Portland cement. A pozzolan is a siliceous or aluminosiliceous material that has a cementitious value and, in the presence of water and finely divided form, chemically reacts with calcium hydroxide produced during the hydration of Portland cement to form hydratable species with cementitious properties. Diatomaceous earth, opal, flints, clays, shales, volatile ash, silica fume, volcanic tuffs, pumice stones and trasses are some of the best known pozzolans. Certain ground granulated blast furnace slags and volatile ash with a high calcium content have both pozzolanic and cementitious properties. Volatile ash is defined in ASTM C618.

The amount of hydraulic cement and pozzolanic material in the extrudable cementitious composition may vary depending on the identities and concentrations of the other components. In general, the combined amount of hydraulic cement and pozzolanic material is in a range of about 25% to about 75% by weight of the extrudable cementitious composition, more suitably in a range of about 35% to about 65% by weight of the cementitious extrudable composition, and most suitably in a range of about 40% to about 60% by weight of the extrudable cementitious composition.

Briefly, within the extruded product, the hydraulic cement forms a paste or cement gel when reacted with water, where the reaction rate can be greatly increased through the use of hardening accelerators or heat curing, and the strength and The physical properties of cementitious composite building products are modulated by a high concentration of fibers. Usually, the amount of hydraulic cement in a cured cementitious composite is described as a dry percentage (e.g.,% dry weight or% dry volume). The amount of hydraulic cement may vary in a range from about 40% to about 95% dry weight, more suitably from about 50% to about 80% dry weight, and much more suitably from about 60% to about 75% by weight dry. It must be recognized that some products may use more or less hydraulic cement, as necessary and depending on the other constituents.

The amount of water within the various compositions described herein can be drastically varied over a large range. For example, the amount of water in the extrudable cementitious composition and fresh extruded material can vary from about 15% by weight of the extrudable cementitious composition to about 75% by weight of the extrudable cementitious composition, more suitably from about 35% to about 65% and much more suitably from about 40% to about 60% by weight of the extrudable cementitious composition. On the other hand, the cured composite or hardened cementitious composite may have free water in less than 10% by weight, more suitably less than about 5% by weight, and most suitably less than about 2% by weight of water; however, additional water can be linked with the rheology modifier, fibers or aggregates.

The amount of water in the extruded material during the rapid reaction period should be sufficient for curing or hydration to provide the finished properties described herein. However, maintaining a relatively low water to cement ratio (ie, w / c) increases the strength of the final cementitious composite products. Accordingly, the ratio of water to actual or nominal cement will typically initially vary from about 0.1 to about 0.6.

While it is desirable for cementitious building products to have properties similar to those of stone, it has been found that cementitious building products prepared using the methods of the present disclosure have lower densities as compared to natural stone and products. of solid surface. More particularly, cementitious composite building products have a density of at least about 1.3 g / cm3 and less than 3.0 g / cm3, more suitably, at least about 1.3 g / cm3 and less than about 2.3 g / cm3, and even more adequately, from about 1.6 g / cm3 to about 1.7 g / cm3, and uniform.

Aggregates are also included in the extrudable cementitious composition to provide hardness to cementitious composite products. More particularly, the harder, stronger aggregates are typically included since these aggregates will deteriorate the pulp strength of the cementitious composite products lower than in conventional products.

The aggregate includes both fine aggregate and coarse aggregate. Examples of suitable materials for coarse and / or fine aggregates include silica, quartz, crushed round marble, glass spheres, granite, limestone, bauxite, calcite, feldspar, alluvial sands or any other durable aggregate and mixtures thereof. In a preferred embodiment, the fine aggregate consists essentially of "sand" and the coarse aggregate consists essentially of "rock" (eg rock of 3/8 inch and / or 3/4 inch) as those terms are understood by those of skill in the technique.

In one aspect, the extrudable cementitious composition (and the cementitious composite product) includes two separate sizes of coarse aggregate (ie, coarser and less coarse aggregates). More particularly, the extrudable cementitious composition may include coarser aggregate such as 3/4 inch rock and less coarse aggregate such as 3/8 inch rock.

It should be recognized that while discussed herein as using two sizes of coarse aggregate, the extrudable cementitious composition can be produced with either only the less coarse aggregate or only the coarser aggregate without departing from the present disclosure.

B. Fibers The extrudable cementitious composition and the extruded cementitious composite building products include a relatively high concentration of fibers compared to conventional concrete compositions. On the other hand, the fibers are typically substantially homogeneously dispersed throughout the cementitious composition in order to maximize the beneficial properties imparted by the fibers. The fibers are present in order to provide structural reinforcement to the extrudable cementitious composition, fresh extruded material and the cementitious composite building product.

Various types of fibers can be used in order to obtain specific characteristics. For example, extrudable cementitious compositions may include naturally occurring organic fibers extracted from hemp, cotton, leaves or stems of plants, hardwoods, softwoods or the like, fibers made of organic polymers, examples of which include polyester nylon (ie polyamides), polyvinyl alcohol (PVA), polyethylene and polypropylene, and / or inorganic fibers, examples of which include glass, graphite, silica, silicates, micro glass made of alkali resistant using borax, ceramics, carbon fibers, carbides, metal materials and the like. Particularly preferred fibers, for example, include glass fibers, woolastanite, abaca, bagasse, wood fibers (e.g., soft pine, southern pine, spruce and eucalyptus), cotton, silica nitride, silica carbide, nitride silica, tungsten carbide and Kevlar; however, other types of fibers can be used.

The fibers used in the manufacture of the cementitious compositions can have a high length-to-width ratio (or "dimensional relationship") because the smaller, longer fibers typically impart more strength per unit weight to the finished composite cement building product. . The fibers can have a dimensional ratio of at least about 10: 1, preferably at least about 50: 1, more preferably at least about 100: 1 and much more preferably greater than about 200: 1.

In one embodiment, the fibers can be used in various lengths such as, for example, from about 0.1 cm to about 2.5 cm, more preferably from about 0.2 cm to about 2 cm, and much more preferably from about 0.3 cm to about 1.5 cm In one embodiment, the fibers can be used in lengths less than about 5 mm, more preferably less than about 1.5 mm, and much more preferably less than about 1 mm.

In a modality, very long or continuous fibers can be mixed in the cementitious compositions. As used herein, a "long fiber" is proposed to refer to a thin long synthetic fiber such that it is longer than about 2.5 cm. As such, a long fiber may be present with lengths ranging from about 2.5 cm to about 10 cm, more preferably about 3 cm to about 8 cm, and much more preferably from about 4 cm to about 5 cm.

The concentration of fibers within the extrudable cementitious compositions can vary widely in order to provide various properties to the extruded composition and the finished cementitious composite product. Generally, the fibers may be present in the extrudable composition in an amount of greater than about 1% by volume of the extrudable cementitious composition, more suitably greater than about 2%, and more suitably greater than about 3%, and even more suitably about 20%, and more suitably from about 3.5% to about 8% by volume in the extrudable cementitious composition.

Additionally, specific types of fiber may vary in quantity in the compositions. For example, in one embodiment, PVA may be present in the extrudable cementitious composition in an amount of about 1.5% to about 3.5% by volume of the extrudable cementitious composition. Soft fibers and / or woods, such as cellulose fibers, may be present in the extrudable cementitious composition in amounts described in the above with respect to the general fibers or present in an amount from about 1.5% to about 5.0% by volume of the cementitious extrudable composition.

In one embodiment, the type of fiber may be selected based on the desired structural characteristics of the finished product comprised of the cementitious composite product, where it may be preferred to have dense synthetic fibers compared to the light natural fibers or vice versa. Typically, the specific gravity of natural or softwood fibers is approximately 1.2. On the other hand, synthetic fibers can have specific gravities ranging from approximately 1 for polyurethane fibers, approximately 1.3 for PVA fibers, approximately 1.5 for Kevlar fibers, approximately 2 for graphite fibers and quartz glass, approximately 2.3 for fibers glass, about 3.2 for silicon carbide and silicon nitride, about 7 to about 9 for most metals with about 8 for stainless steel fibers, about 5.7 for zirconia fibers, to about 15 for tungsten carbide fibers . As such, natural fibers tend to have densities of about 1 or less, and synthetic fibers tend to have densities of about 1 to about 15.

In one embodiment, a mixture of regular or long-length fibers, such as pine, spruce or other natural fibers, can be combined with micro-fibers, such as woolastinite or microglass fibers, to provide unique properties, including increased hardness, Flexibility and resistance to bending, with the larger and smaller fibers acting at different levels within the cementitious composition.

In view of the foregoing, the fibers are added in relatively high amounts in order to produce a cementitious composite building product having increased tensile strength, elongation, deflection, deformability and flexibility. The fibers contribute to the ability of the cementitious composite building product to be sawed, bolted, polished and / or ground to stone.

C. Regulatory Modification Agent In one or more embodiments of the present disclosure, the extrudable cementitious compositions and the cementitious composite building products include a rheology modifying agent ("rheology modifier"). The rheology modifier can be mixed with water and the fibers to help distribute substantially uniformly (or homogeneously) the fibers within the cementitious composition. Additionally, the rheology modifier can impart shape stability to an extruded material. In part, this is because the rheology modifier acts as a binder when the composition is in a fresh state to increase the early fresh strength so that it can be handled in another way to process without the use of molds or other devices. shape retention The rheology modification agent helps control porosity (ie, produces uniformly dispersed pores when the water is removed by evaporation). In addition, the rheology modifying agent can impart increased hardness and flexibility to a cured cementitious composite product which can result in increased deflection characteristics. Thus, the rheology modifier cooperates with the other compositional components in order to achieve a more deformable, flexible, foldable, compactable, hard and / or elastic cementitious building product.

For example, variations in the type, molecular weight, degree of branching, amount and distribution of the rheology modifier can affect the properties of the extrudable cementitious composition, the fresh extruded material and the cementitious composite building products. As such, the type of rheology modifier can be any polysaccharide, proteinaceous material and / or synthetic organic material that is capable of giving or providing the Theological properties described herein. Examples of some suitable polysaccharides, particularly cellulose ethers, include, methylhydroxyethylcellulose, hydroxymethylethylcellulose, carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose and hydroxyethylpropylcellulose, starches such as amylopectin, amylose, starch acetates, hydroxyethyl starch ethers, ionic starches, long chain alkyl starches , dextrins, amine starches, phosphate starches and dialdehyde starches, polysaccharide gums such as seagel, alginic acid, phycocolloids, agar, gum arabic, guar gum, locust bean gum, karaya gum, tragacanth gum and the like. Examples of some proteinaceous materials include collagens, caseins, biopolymers, biopolyesters and the like. Examples of synthetic organic materials that can impart rheology modification properties include petroleum-based polymers (eg, polyethylene, polypropylene), latexes (e.g., styrene-butadiene) and biodegradable polymers (e.g., aliphatic polyesters, polyhydroxyalkanoates, polylactic acid , polycaprolactone), polyvinyl chloride, polyvinyl alcohol and polyvinyl acetate. The clay can also act as a rheology modifier to help disperse the fibers and / or impart shape stability to the fresh extruded intermediate.

The amount of the rheology modifier within the extrudable cementitious composition and the cementitious building product can vary from low to high concentrations depending on the type, branching, molecular weight and / or interactions with other compositional components. For example, the amount of rheology modifier present in the extrudable cementitious compositions may vary from about 0.1% to about 4% by volume of the extrudable cementitious compositions, suitably from about 0.25% to about 2% by volume, even more suitably from about 0.5% to about 1.5% by volume, and much more adequately from about 0.75% to about 1% by volume of the extrudable cementitious compositions. The amount of rheology modifier present in cured cementitious composite products may vary from about 0.5% to about 1% by volume.

Additionally, examples of synthetic organic materials, which are plasticizers usually used in conjunction with the rheology modifier, include polyvinyl pyrrolidones, polyethylene glycols, polyvinyl alcohols, polyvinylmethyl ethers, polyacrylic acids, polyacrylic acid salts, polyvinyl acrylic acids, polyvinylacrylic acid salts, polyacrylimides, polymers of ethylene oxide, polylactic acid, synthetic clay, styrene-butadiene copolymers, latexes, copolymers thereof, mixtures thereof and the like. For example, the amount of plasticizers in the extrudable cementitious composition may vary from nothing plasticizer to about 40% plasticizer by weight, more suitably from about 1% to about 35% plasticizer by weight, even more suitably about 2% by weight. about 30%, and much more suitably from about 5% to about 25% by weight.

D. Filler In one embodiment, the extrudable composition, the fresh intermediate extruded material and the cured cementitious composite product may include fillers. Alternatively, there are cases where filler materials are specifically excluded. The fillers, if used at all, are generally included in smaller quantities and mainly to decrease the cost of extruded products. Because it is desired to obtain extruded products in the form of building material similar to the stone that has the properties of the stone, the fillers must be selected so that they do not produce a product that is too soft or difficult to work with. . Examples of fillers include hard silicate, glass, basalt, granite, calcined bauxite. The additional information that considers the types and amounts of fillers that can be used in the cementitious compositions is known to one of ordinary skill in the art. Fillers can also be chosen to add artistic or aesthetic properties to cementitious composite products.

In one embodiment, the extrudable cementitious compositions may include a widely varying amount of fillers. Specifically, when used, the fillers each independently can be represented in less than about 10% by weight of the extrudable cementitious composition, suitably less than about 7% by weight, more suitably less than about 3% by weight, and much more adequately between about 2% to about 12% by weight of the extrudable cementitious composition.

In one embodiment, the cured cementitious composite products may include a widely varying amount of fillers. Specifically, when used, the fillers each independently can be present in less than about 15% by weight, suitably less than about 10% by weight, more suitably less than about 5% by weight, and much more adequately between about 3% and about 15% by weight. In some cases, fillers such as limestone may be present up to about 70% by weight. For example, when included in a cured cementitious compound, the vermiculite may be present in about 2% by weight to about 20% by weight, and suitably from about 3% by weight to about 16% by weight.

E. Mixtures and Other Materials A wide variety of mixtures and other materials can be added to the extrudable cementitious compositions to give the extrudable cementitious compositions and cementitious composite products made therefrom the desired properties. Examples of mixtures that can be used in the extrudable cementitious compositions of the disclosure include, but are not limited to, hardening accelerators, air entraining agents, strength enhancing amines and other fortifiers, dispersants, water reducers, superplasticizers, agents water binding, viscosity modifiers, corrosion inhibitors, pigments, wetting agents, water soluble polymers, water repellents, permeability reducers, pumping auxiliaries, fungicide mixtures, germicidal mixtures, insecticide mixtures, finely divided mineral mixtures, alkali reactivity reducers, binding mixtures, nucleating agents, volatile solvents, salts, regulating agents, acidic agents, coloring agents and the like, and mixtures thereof.

A hardening accelerator can be included in the extrudable cementitious composition, fresh intermediate extruded material and cementitious composite building product. As described herein, the hardening accelerator can be included to decrease the duration of the induction period or prevent the onset of the rapid reaction period. Accordingly, traditional hardening accelerators such as MgCl2, NaC03, KC03 CaCl2 and the like can be used, but can result in a decrease in the compressive strength of the cementitious composite building product; however, this may be a desirable by-product in order to produce a product that can be sawed, nailed, polished and frosted similar to stone. For example, traditional hardening accelerators can be presented in the fresh intermediate extruded material from about 0.001% to about 5% by total weight, more suitably from about 0.05% to about 2.5% by weight, and much more appropriately about 0.11% to about II by weight.

The retarding agents, also known as retarders, hardening retarders, hydration control or delayed hardening mixtures, can also optionally be used to retard, delay or slow the rate of hydration of the cement. In addition, retarding agents can maintain constant rheology and reduce buildup in the extruder. They can be added to the extrudable composition, fresh extruded material and the cementitious composite building product. Examples of retarding agents include lignosulfonates and salts thereof, hydroxylated carboxylic acids, borax, gluconic acid, tartaric acid, mucic acid and other organic acids and their corresponding salts, phosphonates, monosaccharides, disaccharides, trisaccharides, polysaccharides, others of certain carbohydrates such as sugars and sugar-acids, starch and derivatives thereof, celluloses and derivatives thereof, water soluble salts of folic acid, water-soluble silicone compounds, sugar-acids and mixtures thereof. Exemplary retarding agents are commercially available under the trade name Delvo®, from Masterbuilders (a division of BASF, The Chemical Company, Cleveland, Ohio). Air entraining agents are compounds that entrain microscopic air bubbles in cementitious compositions, which then harden into cementitious composite products that have microscopic air voids. The entrained air remarkably improves the durability of the product exposed to moisture during freeze-thaw cycles. Air entraining agents can also reduce the surface tension of an extrudable cementitious composition in low concentration. Air entrainment can also increase the working capacity of extrudable cementitious compositions and reduce segregation and purging. Examples of suitable air entraining agents include wood resin, sulfonated lignin, petroleum acids, proteinaceous material, fatty acids, resinous acids, alkylbenzene sulfonates, sulfonated hydrocarbons, vinsol resin, anionic surfactants, cationic surfactants, nonionic surfactants, rosin natural, synthetic rosin, inorganic air entrainers, synthetic detergents, the corresponding salts of these compounds and mixtures of these compounds. The air entraining agents are added in an amount to produce a desired level of air in an extrudable cementitious composition.

In another alternative embodiment, the concrete composition does not include any air entraining agent but rather a larger amount of superplasticizer, as discussed below.

Strength enhancing amines are compounds that improve the compressive strength of cementitious composite products made from extrudable cementitious compositions. The resistance enhancing amine includes one or more compounds from the group selected from poly (hydroxyalkylated) polyethyleneamines, poly (hydroxyalkylated) polyethylenepolyamines, poly (hydroxyalkylated) polyethylene imines, poly (hydroxyalkylated) polyamines, hydrazines, 1,2-diaminopropane, polyglycoldiamine, poly- (hydroxylalkyl) amines and mixtures thereof. An exemplary strength enhancing amine is 2,2,2,2 tetrahydroxydiethylenediamine.

Dispersants are used in extrudable cementitious compositions to increase flowability without adding water. The dispersants can be used to decrease the water content in the extrudable cementitious composition to increase the strength without adding additional water. A dispersant, if used, can be any suitable dispersant such as lignosulfonates, beta naphthalene sulfonates, sulphonated formaldehyde melanin condensates, polyaspartates, polycarboxylates with and without polyester units, sulfonate formaldehyde naphthalene condensate resins or oligomeric dispersants. Depending on the type of dispersant, the dispersant can function as a plasticizer, high-range water reducer, fluidizer, anti-flocculating agent and / or superplasticizer.

One class of dispersants includes mid-range water reducers. Mid-range water reducers should at least meet the requirements for Type A in ASTM C 494.

Another class of dispersants includes high-range water reducers (HR R). These dispersants are capable of reducing the water content of a given extrudable cementitious composition, thus as about 10% to about 50%. The HRWRs can be used to increase the strength or to greatly increase the settlement to produce a "flowing" extrudable cementitious composition without adding additional water. The HRWRs that may be used in the present disclosure include those covered by ASTM C 494 and types F and G, and Types 1 and 2 in ASTM C 1017. Examples of HRWRS are described in US Patent No. 6,858,074, which is incorporated herein by reference to the extent to which it is consistent therewith.

The waterproofing mixtures reduce the permeability of the extrudable cementitious composition that has low cement contents, high water-cement ratios or a fine deficiency in the aggregate. These mixtures retard the penetration of moisture into dry concrete and include certain soaps, stearates and petroleum products.

Permeability reducers are used to reduce the at which water under pressure is transmitted through the extrudable cementitious composition (and cementitious composite products). Silica fume, volatile ash, ground slag, natural pozzolans, water reductants and latex can be used to decrease the permeability of the extrudable cementitious composition.

Contraction reducing agents include but are not limited to alkali metal sulfate, alkaline earth metal sulfates, alkaline earth oxides, for example sodium sulfate and calcium oxide.

The finely divided mineral mixtures are powdered materials or powdered form added to the extrudable cementitious compositions before or during the mixing process to improve or change some of the plastic or hardened properties of the Portland cement. Finely divided mineral mixtures can be classified according to their chemical or physical properties as: cementitious materials; pozzolans; pozzolanic and cementitious materials; and nominally inert materials. Nominally inert materials include finely divided raw quartz, dolomites, limestones, marble, granite and others.

The natural and synthetic mixtures are used to color the extrudable cementitious composition for aesthetic and safety reasons. The colorant mixtures are usually composed of pigments and include carbon black, iron oxide, phthalocyanine, dark ocher, chromium oxide, titanium oxide and cobalt blue.

In one embodiment, a substantially cured cementitious composite product that is reinforced with fibers can be coated with a protective or sealant material such as a paint, dye, varnish, texturizing coating and the like. As such, the coating can be applied to the cementitious composite building product after it is substantially cured. For example, the cementitious building product can be bonded such that the fibers present on the surface are of a shade different from the rest of the product, and / or texturized to resemble a stone product.

Sealants known in the concrete industry can be applied to the surface and / or incorpod into the cementitious composition in order to provide water-proofing properties. These include silanes and siloxanes.

MANUFACTURING OF CEMENTED COMPOSITE PRODUCTS Figure 1 is a schematic diagram illustng one embodiment of a manufacturing system and equipment that can be used during the formation of an extrudable cementitious composition, fresh intermediate extruded material, cementitious composite product and / or cementitious composite building product. It should be recognized that this is only an illustd example for the purpose of describing a general processing system and equipment, where various additions and modifications can be made thereto in order to prepare cementitious composite products (and building products or products). building) . Also, the schematic representation should not be considered in any way limiting as to the presence, arrangement, shape, orientation or size of any of the features described in connection therewith. With that said, a more detailed description of the system and equipment that may be prepared by extrudable cementitious compositions as well as cementitious composite building products that are in accordance with the present disclosure is provided.

Referring now to Figure 1A, an embodiment of an extrusion system 10 is provided in accordance with the present disclosure. Such an extrusion system 10 includes a first mixer 16, a second optional mixer 18 and an extruder 24. The first mixer 16 is configured to receive at least one feed of materials through at least one first feed stream 12 to be mixed in a first mixture 20 (for example, in one embodiment the first mixture 20 is the fibrous mixture described in the above). After suitable mixing, which can be carried out under high shear stress, while maintaining a tempere below that which acceles hydon, the first mixture 20 is removed from the first mixer 16 as a flow of material ready for further processing.

By mixing the first mixture 20 apart from any additional components, the respective mixed components can be distributed homogeneously throughout the composition. For example, it may be advantageous to mix the fibers homogeneously with at least the rheology modifier and water before combining them with the additional components. As such, the rheology modifier, the fibers and / or water are mixed under high shear stress to increase the homogeneous distribution of the fibers therein. The rheology and water modification agent forms a plastic composition having high strain and viscosity which is capable of transferring the shear forces of the mixer down to the level of the fiber. In this way, the fibers can be dispersed homogeneously throughout the fibrous mixture using much less water than that required in conventional processes, which typically require up to 99% water to disperse the fibers.

The second optional mixer 18 has a second feed stream 14 that supplies the material that is mixed in a second mix 22, where such mixing can be increased by the inclusion of a heating element. For example, the second mixer 18 can receive and mix the additional components, such as additional water, hardening accelerators, hydraulic cement, plasticizers, aggregates, nucleating agents, dispersants, polymeric binders, volatile solvents, salts, regulating agents, acidic agents, coloring agents, fillers and the like before being combined with other components to form the extrudable cementitious composition. The second mixer 18 is optional because the additional components could be mixed with the fibrous mixture in the first mixer 16.

As in the illustrated schematic diagram, the extruder 24 includes an extruder screw 26, optional heating elements (not shown) and a mold head 28 with a mold opening 30. Optionally, the extruder can be a single screw, double screw and / or a piston type extruder. After the first mixture 20 and the second mixture 22 enter the extruder they can be combined and mixed in an extrudable cementitious composition.

By mixing the components, an interface is created between the different components, such as the rheology modification agent and the fibers, which allows the individual fibers to move away from each other. By increasing the viscosity and strain strain with the rheology modifying agent, more fibers can be substantially homogeneously distributed throughout the mixture and the final cured product. Also, the cohesion between the different components can be increased to increase the interparticle and capillary forces for increased mixing and shape stability after extrusion. For example, the cohesion between the different components can be similar to the clay so that the fresh extruded material can be placed on a pottery wheel and made similar to the common clays that are manufactured in the pottery.

In one embodiment, additional feed streams (not shown) can be located at any position along the length of the extruder 24. The availability of additional feed streams can allow the manufacturing process to add certain components at any position to modifying the characteristics of the extrudable cementitious composition during mixing and extrusion as well as the characteristics of the fresh intermediate extruded material after extrusion. For example, in one embodiment it may be advantageous to supply the hardening accelerator in the composition within about 60 minutes to within about 1 second before being extruded. More preferably, the hardening accelerator is mixed into the composition within about 45 minutes to about 5 seconds before being extruded, even more adequately within about 30 minutes to about 8 seconds, and much more appropriately within about 20 minutes to about 10 seconds before being extruded. This may allow the fresh intermediate extruded material to be configured for increased shape stability and a shortened induction period before the start of the rapid reaction period.

With continued reference to Figure 1A, as the extrudable cementitious composition moves to the end of the extruder 24, it passes through the mold head 28 before being extruded into the mold opening 30. The mold head 28 and the mold opening 30 can be configured in any shape or arrangement while producing a fresh intermediate extruded material (also referred to herein as fresh extruded material or extruded material) that is capable of being further processed or finished into a building product Cementitious compound In the illustrated embodiment, it may be advantageous for the mold opening 30 to have a circular diameter so that the extruded material 32 has a rod-like shape. Other exemplary cross-sectional shapes are illustrated in Figure 1C, including hexagonal form 42, rectangular 44, square 46 or beam I 48. Extruded products can be characterized as being immediately stable in shape while in the fresh state . That is, the extruded material can be processed immediately without deformation, wherein the processing can include cutting, sawing, shaping, buffing, grinding, forming, punching and the like. As such, the extruded material in the fresh state does not need to be cured before being prepared in the size, configuration or shape of the finished cementitious composite building product. For example, processing in the fresh state may include the following: (a) creation of stone-like surfaces, by grinding, sawing, cutting, polishing or the like, having specified dimensions, such as width, thickness, length, radius , diameter, surface texture and the like; (b) folding the extruded material to form a curved cementitious product, which can be of any size and shape, such as a curved edge or counter, and other ornamental and / or structural members; (c) creation of products that have lengths of 6 feet 9 inches, 8 feet 9 inches, 9 feet 1 inch, 27 feet, 40 feet, 41 feet, 60 feet, 61 feet, 80 feet, 81 feet and the like; (d) roller texturing, which can impart stone-like and / or marble-like surfaces to the cementitious composite building product; (e) having the surface painted, waterproofed or otherwise coated, which may apply coatings comprised of silanes, siloxanes, latex and the like; and (1) transported, sent or otherwise moved and / or handled. Also, byproducts that are produced from fresh processing can be placed in the feed and reprocessed compositions. Thus, fresh cementitious byproducts can be recycled, which can significantly reduce waste and manufacturing costs.

Figure IB is a schematic diagram of a mold head 29 that can be used with the extrusion process of Figure 1A. As such, the mold head 29 includes a mold opening 30 having a hole forming member 31. The hole forming member 31 can be circular as shown, or have any cross-sectional shape. As such, the hole forming member 31 can form a hole in the extruded material, which is shown in Figure 1C. Since the extruded material can be immediately stable in the extrusion, the hole can retain the size and shape of the hole forming member 31. Additionally, several mold heads having hole forming members that can produce annular extruded materials are well known in the art and can be adapted or modified, if necessary, to be usable with the extrusion processes according to the present disclosure.

Referring now to Figure 1C, additional embodiments of extruded materials 40 are depicted. Accordingly, the mold head and mold opening of Figure 1A or IB can be modified or altered to provide extruded materials 40 having several areas of extruded material. cross section, wherein the cross-sectional area of the extruded material 40 can be substantially the same as the cross-sectional area of the mold opening. For example, the cross-sectional area may be a hexagon 42, rectangle 44 (for example, two by four, one by ten, etc.) square 46, beam I 48 or a cylinder 50, optionally having a continuous hole 49. Also, additional cross-sectional shapes can be prepared by extrusion. More particularly, the mold head and the mold opening in Figure IB can be used so that the hexagon 42, rectangle 44, square 46, beam I 48 or cylinder 50 can optionally include continuous circular holes 51, rectangular holes 53, square holes 57 or similar ones. Also complex mold heads and openings can be used to prepare the cylinder 50 having the continuous hole 49 and a plurality of smaller holes 51. On the other hand, any general cross sectional shape can be further processed in such a specific form, as for example, a square form of two by four to one of four by four. Alternatively, the mold orifice can produce oversized products which are then trimmed to the desired specifications in order to ensure the greatest uniformity.

Accordingly, the above processes may be usable to extrude construction or building products with one or more continuous holes to reduce the weight of the products. For example, a counter-like material can be extruded having one or more holes in which reinforcement bar can be inserted, either while in the fresh state or after curing. In the case of a cured counter material, the reinforcement bar can be held in place within the hole using epoxy or other adhesive to provide strong bond between the reinforcement bar and the material. For example, the cylinder 50 of Figure 1C, as well as the other shapes, can be manufactured in large counters. These structures may optionally include a large interior opening 49 to reduce mass and cost, along with smaller holes 51 in the wall to allow insertion of the strengthening reinforcing bar, as shown.

In one embodiment, the extrudable cementitious composition is deaerated before being extruded. While some processes may employ a specific deaeration process to remove a substantial amount of air from the extrudable cementitious composition, other processes may remove air through the mixing process that occurs in the extruder. In any case, active or passive deaeration can provide an extruded material that does not have large air voids or cellular formations. In general, it is preferable to deaerate the extrudable cementitious composition since this decreases the porosity of the composition, and in this way, increases the resistance to the final product. For example, a deaerated cementitious compound may have trapped air in an amount of from about 0% to about 10%, more suitably from about 0.1% to about 5%, and much more suitably from about 0.2% to about 3%. Thus, the extruded material and the resultant cementitious composite building product can be manufactured to be substantially or completely free of any of the multi-cellular formations.

In one embodiment, the extruded material can also be processed in a dryer or autoclave. The dryer can be useful for drying the extruded material to remove excess water from the hardened product. In this embodiment, the extruded material can be processed through an autoclave in order to increase the curing speed and the development of strength to produce an increase in product strength from about 50% to about 100%.

Figure 2 is a schematic diagram depicting an alternative extrusion process that can be used to prepare cementitious composite building products in accordance with the present disclosure. As such, the extrusion process can be considered for use in a roll extrusion system 200 and uses rolls to extrude the extrudable cementitious composition into a fresh intermediate extrudable material. Such roller extrusion system 200 includes a mixer 216 configured to receive at least one feed of materials through a feed stream 212 to be mixed in a mixture 220. After suitable mixing, which can be performed as described in FIG. present, the mixture 220 is stirred in the mixer 216 as a flow of material ready for further processing.

The mixture 220 is then applied to a conveyor 222 or other similar port to move the extrudable cementitious composition from the application site. This allows the composition to be formed in a cement flow 224 that can be processed. As such, the cement flow 224 can be passed under a first roll 226 which fits a predetermined distance from the conveyor 222 and which has a predefined cross-sectional area with respect to it, which can press or form the cement flow 224 in a fresh intermediate extruded material 228. Optionally, the conveyor 222 can then supply the fresh intermediate extruded material 228 through a first calender 230 comprised of an upper roller 230a and a lower roller 223b. The calender 230 can be configured to have a predefined cross-sectional area so that the fresh intermediate extruded material 228 is further shaped and / or compressed into a shaped fresh intermediate extruded material 242. Also, a second optional calender 240 comprised of a first roller 240a and a second roller 240b can be used in place of the first calender 230 or in addition thereto. A combination of calenders 230, 240 may be favorable to provide a fresh intermediate extruded material that is substantially shaped as desired.

Alternatively, the first roll 226 can be excluded and the cement flow 224 can be processed through any number of calenders 230, 240.

Additionally, the shaped fresh intermediate extruded material 242, or other extruded material described herein, such as the process illustrated in Figure 1A, can be further processed by a processing apparatus 244. The processing apparatus 244 can be any type of equipment or system used to process the fresh intermediate extruded materials as described herein. As such, the processing apparatus 244 can saw, polish, grind, cut, bend, coat, dry or otherwise shape or further process the formed fresh intermediate extruded material 242 into a processed extruded material 246. Also, the by-product 260 obtained of the processing apparatus 244 can be recycled in the feed composition 212, or applied to the conveyor 222 together with the mixture 220.

In one embodiment, a combined curing / drying process can be used to cure and dry the hydraulic cement to form the extruded cementitious compound. For example, the combined curing / drying process can be performed at a temperature of about 75-95 ° C for 48 hours in order to obtain approximately 80% of the final strength. However, larger blocks may take additional time in any curing and / or drying process. In another embodiment, the combined curing / drying process can be conducted in an autoclave, for example, the autoclave can cure / dry at a temperature of about 190 ° C, at about 12 bars, for about 12 hours.

Optionally, the extruded material can be covered in plastic and / or stored for a period of time to allow curing of the extruded material. This may allow the cured material to harden over time in order to produce the necessary strength for the cured cementitious composite product. For example, after 28 days, the cured cementitious composite product may have approximately 80% ultimate strength, and may be placed in a dryer to remove residual water.

In another embodiment, the combined steam curing and autoclaving processes are used to cure the hydraulic cement. Typically, the cement is initially cured with steam for about 1 to about 6 hours, and then autoclaved at temperatures of about 190 ° C or higher at 12 bars for about 12 hours. When placed in an autoclave, the resulting cement product obtains approximately 100% of the additional strength.

In one embodiment, the fresh intermediate extruded material can also be processed by causing or allowing the hydraulic cement within the fresh intermediate extruded material to be hydrated or otherwise cured to form a solidified cementitious composite building product. As such, the cementitious composite building product can be prepared to be stable in form immediately after being extruded to allow handling thereof without breaking. More preferably, the extrudable cementitious composition or fresh intermediate extruded material can be stable in form within minutes, more adequately within 10 minutes, still more adequately within 5 minutes, and much more conveniently within 1 minute after being extruded. The more optimized and preferred composition and processing can result in a fresh intermediate extruded material that is stable in extrusion form. The use of a rheology modifying agent can be used to produce extruded materials that are immediately stable in shape even in the absence of hydration of the hydraulic cement binder.

In order to achieve stability in shape, the manufacturing process can either simply allow the fresh intermediate extruded material to settle and harden without any additional processing or it can be caused to hydrate and / or harden. When manufacturing includes causing the fresh intermediate extruded material to be hydrated, harden or otherwise cure, the manufacturing system may include a dryer, heater or autoclave. The dryer or heater can be configured to generate enough heat to eject or evaporate water from the extruded material to increase its stiffness and porosity or induce the rapid reaction period. On the other hand, the autoclave can provide pressurized steam to induce the start of the rapid reaction period.

In one embodiment, the fresh intermediate extruded material can be left or induced to initiate the rapid reaction period as described herein in addition to including a hardening accelerator within the extrudable cementitious composition. As such, the fresh intermediate extruded material can be induced to initiate the rapid reaction period by altering the temperature of the extruded material or by changing the pressure and / or relative humidity. Also, the rapid reaction period can be induced by setting the hardening accelerator to start the reaction within a predetermined period of time after it is extruded.

In one embodiment, the preparation of a cementitious composite or cementitious composite building product may substantially include hydration or otherwise curing the fresh intermediate extruded material in the cementitious composite building product within a shortened period, or a reaction rate faster, compared to conventional concretes or other hydraulically hardenable materials. As a result, the cementitious composite building product may be substantially cured or hardened, depending on the type of binder being used, within about 48 hours, more adequately within about 24 hours, even more appropriately within 12 hours, and much suitably within. 6 hours. Thus, the manufacturing system and process can be configured in order to obtain fast curing rates so that the cementitious composite building product can be further processed or terminated.

In one embodiment, a hardened or cured cementitious composite can be further processed or finished. Such processing may include sanding, cutting, drilling, polishing, grinding and / or shaping the cementitious composite product into a desired shape, wherein the composition leads to such shaping. Accordingly, when a cementitious composite building product is cut, the fibers and the rheology modifier can contribute to straight cutting lines that can be formed without cracking or chipping the cut surface or internal aspects of the material. This allows the cementitious composite building product to be a stone substitute because a larger slab of material can be purchased by a consumer and cut with the standard equipment in the desired shapes and lengths.

In one embodiment, the fresh intermediate extruded material stable in shape can be processed through a system that modifies the external surface of the product. An example of such a modification is to pass the fresh intermediate extruded material through a calender or series of rollers that can impart a stone-like appearance. As such, the cementitious composite building product can be a stone substitute that has the aesthetic appearance and texture of the stone or other solid surface material. Also, certain dyes, dyes and / or pigments can be applied to the surface or dispersed within the cementitious composite building product to achieve the color of various types of stones.

The fresh extruded intermediates can also be reformed while in a fresh state to produce, for example, curved products or other building products having a desired radius. This is a significant advantage over traditional stone products, which are difficult to give them curved shape and / or which must be polished and / or ground to have a curved profile. In one embodiment, the cementitious composite building product can be sanded and / or polished in a manner that exposes the fibers on the surface. Due to the high percentage of fiber in the product, a large number of fibers can be exposed on the surface. This can provide interesting and creative textures that can increase the aesthetic qualities of the product.

BUILDING PRODUCTS CEMENT COMPOUNDS The present disclosure provides the ability to manufacture cementitious composite building products that have virtually any desired size and shape, either extruded into the desired shape or later cut, polished, frosted or otherwise shaped to the desired size and shape. Examples include architectural products such as countertops, tiles, exterior cladding, shingles and the like, as well as structural products such as pre-cast members or pre-formed with extrusion or molded products injected. Accordingly, the cementitious composite building product can be a load carrier or carry no load. Thus, the cementitious composite building product can be used as a stone substitute for "almost any building application.

The cured cementitious composite product can be configured to have several properties in order to function as a stone substitute. An example of a cured cementitious composite product that can function as a stone substitute can bring any of the following properties: have a hardness and / or stiffness similar to stone and other solid surface materials such to prevent cracking and splitting of the product; have a high compressive strength to allow support and durability for use in products similar to stone; and high flexural strength to allow flexibility for use in product handling and / or bending and curved appearance of the product in a desired product form. These properties are achieved while maintaining the volume density of the product significantly lower than that of natural stone and solid surface materials.

In one embodiment, the fresh intermediate extruded material or cementitious composite can be prepared in a cementitious composite building product as described above. As such, in one embodiment the cured cementitious composite product can be characterized as having a specific gravity and even pores or cell formations that can be greater than about 1.3 or vary from about 1.3 to about 3.0, more suitably from about 1.3 to about 2.3. , and much more appropriately from about 1.6 to about 1.7.

One embodiment of the cured compound can be characterized by having a compressive strength of at least about 6,000 psi, more suitably at least about 8,000 psi, and even more adequately at least about 10,000 psi.

In one embodiment, the cured compound can have a flexural strength of at least about 1,500 psi, more suitably at least about 2,000 psi, more suitably at least about 3,000 psi, more suitably at least about 4,000 psi, and even more adequately, from about 2,500 psi to about 6,000 psi. For example, in one embodiment, the cured compound has a flexural strength of up to about 5,700 psi.

With these foregoing resistances, it should be recognized by one skilled in the art that cured composites can function as substitutes for natural stone and solid surface products without the use of reinforcing members such as reinforcing bar or glass fibers. This provides a less expensive and less labor-intensive substitute for building materials.

In one embodiment, the cured compound may further have a flexural modulus of at least about 500,000, more suitably at least about 1,000,000, still more suitably from about 500,000 psi to about 2,000,000 psi, and even more adequately approximately 1,000,000 psi to approximately 1,750,000 psi.

As noted in the foregoing, the cured compound further includes a hardness similar to that of stone and other solid surface materials. More particularly, the cured cementitious composite product includes a hardness of at least 4 MOH; more adequately, at least about 5 MOH; more suitably, at least about 6 MOH, and even more suitably, from about 7 MOH to about 8 MOH. EXAMPLES OF MODALITIES OF THE DESCRIPTION Example 1 An extrudable cementitious composition was prepared according to the present disclosure. The components of the composition were mixed according to the normal mixing procedures described in the above and in the references incorporated herein. The extrudable composition was formulated as illustrated in Table 1 Table 1 After mixing, the composition was extruded through a mold head having a rectangular opening of about 1 inch by about 4 inches. Four rectangular table samples were prepared. As the first board exited the extruder, it was twisted in opposite directions and placed on a flat surface. The second board was removed in a plastic hammock and placed immediately on the first board on the flat surface. The third board was pulled directly on the flat surface without agitation. All three previous samples were placed directly in the steam curing chamber to be removed in 7 days. The fourth sample was extruded and allowed to cure on the conveyor without any movement or agitation. Several physical properties of the boards were tested after 24 hours, 48 hours, 32 hours, 7 days and 9 days of curing. The results (averaged) are shown in Table 2.

Table 2 The tables were then examined visually to determine if there was a difference in appearance caused by the different management methods. All the boards, except for the second board, which was placed in the plastic hammock, appeared to have cracks, however, it was determined that the cracks were the alignment of silica sand.

Example 2 An extrudable composition was prepared to produce a Dahl pavement tile according to the present disclosure. The components of the composition were mixed according to the normal mixing procedures described in the above and in the references incorporated herein. The extrudable composition was formulated as illustrated in Table 3.

Table 3 Component Amount in the Composition HW = hardwood After mixing, the composition was extruded. Three samples of the extruded composition were cured in plastic at ambient conditions and then placed in a steam chamber. The samples were then placed in a dry oven until they reached the weight balance. The samples were finally characterized by testing volume density, flexural strength, flexural modulus and hardness. The results are shown in Table 4.

Table 4 As several changes could be made in the above constructions and methods without departing from the scope of the description, it is proposed that all the material contained in the above description and shown in the accompanying drawings will be interpreted as illustrative and not in a limiting sense.

Claims

1. A cementitious composite product having properties similar to stone, the product characterized in that it comprises an extrudable cementitious composition comprised of a hydraulic cement, aggregate, a rheology modifying agent and fibers substantially homogeneously distributed through the extrudable cementitious composition. included in an amount greater than about 2% (by volume of the extrudable cementitious composition), wherein the cementitious composite has a hardness value of at least 4 MOH and a bulk density of about 1.3 g / cm3 at about 2.3. g / cm3.

2. The cementitious composite product according to claim 1, characterized in that the extrudable cementitious composition comprises fine aggregate and coarse aggregate.

3. The cementitious composite product according to claim 1, characterized in that the fibers are included in an amount of about 3% to about 20% (by volume of the extrudable cementitious composition).

. The cementitious composite product according to claim 1, characterized in that the fibers comprise cellulose fibers and polyvinyl alcohol fibers.

5. The cementitious composite product according to claim 4, characterized in that the extrudable cementitious composition comprises from about 1.5% (by volume of the extrudable cementitious composition) to about 5.0% (by volume of the extrudable cementitious composition) of cellulose fibers and approximately 1.5% (by volume of the extrudable cementitious composition) to about 3.5% (by volume of the extrudable cementitious composition) of polyvinyl alcohol fibers.

6. The cementitious composite product according to claim 1, characterized in that the rheology modification agent is included in an amount of about 0.1% (by volume of the extrudable cementitious composition) to about 4% (by volume of the extrudable cementitious composition) .

7. The cementitious composite product according to claim 1, characterized in that the cementitious composite product has a hardness value of at least about 5 MOH.

8. The cementitious composite product according to claim 1, characterized in that the cementitious composite product has a compressive strength of at least about 6,000 psi.

9. The cementitious composite product according to claim 1, characterized in that the cementitious composite product has a compressive strength of at least about 8,000 psi.

10. The cementitious composite product according to claim 1, characterized in that the cementitious product has a compressive strength of at least about 10,000 psi.

11. The cementitious composite product according to claim 1, characterized in that the cementitious composite product has a flexural strength of at least about 1,500 psi.

12. The cementitious composite product according to claim 1, characterized in that the cementitious composite product has a flexural strength of at least about 4,000 psi.

13. The cementitious composite product according to claim 1, characterized in that the cementitious composite product has a flexural strength of about 5,700 psi and a bulk density of about 1.6 g / cm3 to about 1.7 g / cm3.

14. The cementitious composite product according to claim 1, characterized in that it does not comprise a reinforcing member.

15. The cementitious composite product according to claim 1, characterized in that it also comprises at least one mixture in the extrudable concrete composition, wherein the mixture is selected from the group consisting of hardening accelerators, air entraining agent, amines increasing resistance and other fortifiers, dispersants, water reducers, superplasticizers, water binding agents, viscosity modifiers, corrosion inhibitors, pigments, wetting agents, water soluble polymers, water repellents, permeability reducers, mixtures of finely divided minerals, nucleating agents, volatile solvents, salts, regulating agents, acidic agents, coloring agents and mixtures thereof.

16. The cementitious composite product according to claim 1, characterized in that the cementitious composite product is capable of use in a counter, tile, exterior cladding and tiles.

17. A method for manufacturing a cementitious composite product having properties similar to stone, the method characterized in that it comprises: jointly mixing water, fibers and a rheology modifying agent to form a fibrous mixture in the. which fibers are substantially homogeneously dispersed; adding a mixture of hydraulic cement and aggregate to the fibrous mixture to produce an extrudable cementitious composition having a plastic consistency and including fiber in a concentration greater than about 2% by volume of the extrudable cementitious composition; extruding the extrudable cementitious composition into a fresh intermediate extruded material having a predefined cross-sectional area, the extruded material which is stable in shape in the extrusion and capable of substantially retaining the cross-sectional area to allow handling without breaking; Y causing or allowing the hydraulic cement to cure to form the cementitious composite product, wherein the cementitious composite has a hardness value of at least 4 MOH and a bulk density of about 1.3 g / cm3 to about 2.3 g / cm3.

18. The method in accordance with the claim 17, characterized in that the extrudable cementitious composition comprises fine aggregate and coarse aggregate.

19. The method according to claim 17, characterized in that the fibers are included in an amount of about 3% to about 20% (by volume of the extrudable cementitious composition).

20. The method according to claim 17, characterized in that the fibers comprise cellulose fibers and polyvinyl alcohol fibers.

21. The method according to claim 20, characterized in that the extrudable cementitious composition comprises from about 1.5% (by volume of the extrudable cementitious composition) to about 5.0% (by volume of the extrudable cementitious composition) of cellulose fibers and from about 1.5 % (by volume, of the extrudable cementitious composition) to about 3.5% (by volume of the extrudable cementitious composition) of polyvinyl alcohol fibers.

22. The method according to claim 17, characterized in that the extrudable cementitious composition comprises from about 0.1% (by volume of the extrudable cementitious composition) to about 4% (by volume of the extrudable cementitious composition) of the rheology modifying agent.

23. The method in accordance with the claim 17, characterized in that the cementitious composite product has a hardness value of at least about 5 MOH.

24. The method according to claim 17, characterized in that the cementitious composite product has a compressive strength of at least about 6,000 psi.

25. The method according to claim 17, characterized in that the cementitious composite product has a compressive strength of at least about 8,000 psi.

26. The method according to claim 17, characterized in that the cementitious composite product has a compressive strength of at least about 10,000 psi.

27. The method according to claim 17, characterized in that the cementitious composite product has a flexural strength of at least about 1,500 psi.

28. The method in accordance with the claim 17, characterized in that the cementitious composite product has a flexural strength of at least about 4,000 psi.

29. The method according to claim 17, characterized in that the cementitious composite product has a flexural strength of about 5,700 psi and a density in volume of about 1.6 g / cm3 to about 1.7 g / cm3.

30. The method according to claim 17, characterized in that the cementitious composite product does not comprise a reinforcing member.

31. The method according to claim 17, characterized in that it further comprises adding at least one mixture to the fibrous mixture, wherein the mixture is selected from the group consisting of hardening accelerators, air entraining agents, resistance enhancing amines and other fortifiers, dispersants, water reducers, superplasticizers, water binding agents, viscosity modifiers, corrosion inhibitors, pigments, wetting agents, water soluble polymers, water repellents, permeability reducers, finely divided mineral mixtures, agents of nucleation, volatile solvents, salts, regulating agents, acidic agents, coloring agents and mixtures thereof.

32. The method according to claim 17, characterized in that the cementitious composite product is capable of use in a counter, tile, exterior cladding and tiles.